Curta Universal-Rechenmaschine
Type I #39172 (c.1958)

The Curta is a small, hand-cranked, mechanical calculator invented by Curt Herzstark while he was a prisoner in the Buchenwald concentration camp. Introduced in 1948, it sports an extremely compact design & will perform various arithmetic functions including roots & cubes. A variant of Gottfried Leibniz's Arithmometer, it accumulates values on cogs, which are added by a stepped-drum mechanism using the method of complements. This is a technique used to subtract one number from another only through addition of positive numbers. The Curta was extremely popular with rallyists & surveyors, but fell out of favor in the 70s due to the advent of the modern electronic calculator. The larger Type II introduced in 1954, has greater numeric capacity than the original. They were produced in Liechtenstein by Contina AG Mauren through November, 1970 with an estimated 140,000 total units... all Y2K compliant!